New features of NFPA 72-2013

By Raymond A. Grill, PE, FSFPE, LEED AP, Arup, Washington, D.C.

03/21/2013

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Chapter 12: Circuits and pathways

Chapter 12 was introduced in NFPA 72-2010 and defines the classification of circuits and pathways based on performance characteristics. It also identifies the criteria for different levels of pathway survivability when pathways are required to survive exposure to fire based on other requirements of the code.

A new requirement has been added in paragraph 12.2.4.2 mandating that transient protection be provided for all signaling system circuits entering or leaving a building.

The performance characteristics for the various pathway designations have been expanded to further clarify the intent of the performance and resulting signals required under fault conditions. Language has also been added to differentiate expectations for performance for nonconductive circuits (i.e., wireless, fiber).

The installation limitations for Class A and X circuits have been moved from chapter 23, Protected Premises, to chapter 12. These requirements identify separation of runs and limitations on using the same assembly for outgoing and return circuit runs.

A new section 12.5 has been added to the chapter, which addresses shared pathways. This section puts level designations on life safety and non-life-safety data over common pathways. Segregation of data may be required depending on the type of data being transmitted.

Chapter 14: Inspection, testing, and maintenance

A new allowance has been added in paragraph 14.2.3.2. It allows the property owner to delegate the authority and responsibility for inspecting, testing, and maintaining the fire protection systems to the occupant of a building. This delegation of authority has to be documented in a lease, written use agreement, or management contract. A copy of the written agreement must be provided to the AHJ if requested.

The visual inspection and testing frequency tables have been consolidated with the methods table. The methods for conducting the visual inspection and the physical testing have been provided in a new column adjacent to the frequency requirement for the specific component for ease of use

Chapter 17: Initiating devices

Spacing for spot-type smoke detectors was expanded to allow for either a maximum of 30 ft nominal spacing between detectors or placement such that all points on the ceiling are within a distance of 0.7 times the nominal 30 ft spacing. The current and past versions of the code intended to allow placement such that all points on a ceiling are 0.7 times the 30 ft nominal spacing. The code now explicitly states this allowance in paragraph 17.7.3.2.3.1.

A new paragraph 17.7.6.3.3.1 explicitly requires that smoke detector spacing be reduced when the airflow rate in the area being protected is greater than 8 minutes per air change (7.5 air changes per hour).

Chapter 18: Notification appliances

Language has been added to the code (18.4.1.4.2 and 18.5.1.2) noting that audible signal and visual signal coverage are required only in occupiable areas. This clarifies the intent of the code. A definition of “occupiable” has also been added to chapter 3; it notes that an occupiable area is an area of a facility occupied by people on a regular basis.

Language has been added (18.4.1.4.1. 18.4.1.4.3, 18.5) that requires the designer to identify what areas will be provided with audible and visual signals, and the ambient and design sound pressure levels.

The criteria for application of the distinctive evacuation signal (three-pulse temporal pattern) have been expanded. The signal was required and allowed only to be used when signaling occupants to evacuate the building. The three-pulse temporal signal is now also required to be used to provide a signal for occupants to relocate from a zone to another zone within the building.

While the code has never required quantitative measurement of intelligibility, paragraph 18.4.10.4 was added to specifically indicate that it is not required.

Table 18.5.5.4.1(a) addressing spacing and ratings of wall-mounted strobes has been revised by deleting the column that provided criteria for two lights per room installed on opposing walls.

Reflecting the increased use of textual and graphical messages for emergency communication, a new section 18.9.4 addresses character and symbol requirements for these appliances and messages and includes a new table specifying minimum criteria.

Chapter 21: Emergency control function interfaces

An exception was added to paragraph 21.3.3 that allows a waterflow switch, solely serving sprinklers at the bottom of an elevator pit, to actuate elevator recall.

An entire section (21.6) has been added addressing occupant evacuation elevators and how the fire alarm system is required to interface with these elevator systems.

Chapter 23: Protected premises fire alarm systems

A requirement was added in paragraph 23.6.1 that limits the maximum number of addressable devices that can be out of service due to a single fault on a pathway. This will require more diligence in system layout and the potential use of isolation modules to limit the number of devices that could be affected by a single fault.

Chapter 24: Emergency communication systems

A new concept has been added to chapter 24 that requires emergency communications used for mass notification systems to be categorized into layers. The categorization must be included in the design documentation of the systems. The code defines the layers as:

Layer 4: notification of people by public means such as radio or television.

Conclusion

This article highlights a number of changes in NFPA 72-2013 that can be incorporated into current designs. There are also a number of requirements that designers will want to be aware of so that when the 2013 edition becomes applicable to projects, it will be easier to incorporate the requirements into the designs.

Ray Grill is a principal with Arup. He has been a member of NFPA 72 Technical Committees for more than 29 years and currently serves as the chair of the Technical Committee on Notification Appliance. He is also member of the NFPA Technical Correlating Committee for Automatic Sprinkler Systems and serves on the Technical Committee on Building Services and Fire Protection Equipment for NFPA 101/5000. He is a member of the Consulting-Specifying Engineer editorial advisory board.